EXPLANATION OF PLATES 
All of the figures have been outlined as far as possible with the camera lucida, 
those of plate 1 at an initial enlargement of approximately 2875 diameters, those 
of plate 2 at approximately 3800 diameters. At so great enlargements it has, 
of course, been necessary to correct the outlines extensively and to add much 
of the finer detail free hand. In reproducing, the figures have been reduced 
uniformly, those of plate 1 to an enlargement of 2300 diameters, those of plate 2 
to 3350 diameters. In every case the method employed in the preparation of 
the original object has been indicated. 
ABBREVIATIONS 
A, acrosome j, juxtanuclear body 
a, acroblast n, nucleus 
G, Golgi remnant s, spermatid remnant 
